Premium
Growth rates of male and female equine embryos between Days 6 and 15 of pregnancy
Author(s) -
ROMAGNANO A.,
BETTERIDGE K. J.,
RICHER C. L.,
SIROIS J.,
KING W. A.
Publication year - 1989
Publication title -
equine veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 87
eISSN - 2042-3306
pISSN - 0425-1644
DOI - 10.1111/j.2042-3306.1989.tb04671.x
Subject(s) - conceptus , ovulation , biology , embryo , pregnancy , andrology , horse , pregnancy rate , zoology , medicine , gestation , genetics , paleontology
Summary To see whether any indication could be found that male conceptuses might develop more rapidly than females in the horse, as they do in several other mammals, pre‐attachment growth rates of female and male conceptuses were estimated from composite curves derived from the diameters of 36 female and 39 male conceptuses each measured once when collected at known times between six and 15 days after ovulation. The conceptuses were sexed cytogenically during the course of a previously reported study. The overall rates of growth (increase in conceptus diameter) were not significantly different for males and females. However, on any given day there was great variation in size amongst embryos and much overlap between the sizes of males and females. It is concluded that comparison of the growth rates of individual embryos, obtained by repeated echographic measurements, might reduce this variability and be a more useful means of continuing this investigation.